140 research outputs found

    Acute lower respiratory tract infection due to respiratory syncytial virus in a group of Egyptian children under 5 years of age

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    <p>Abstract</p> <p>Background and aim</p> <p>Respiratory syncytial virus (RSV) is one of the most important causes of acute lower respiratory tract infections (ALRTI) in infants and young children. This study was conducted to describe the epidemiology of ALRTI associated with RSV among children ≤ 5 years old in Egypt.</p> <p>Patients and Methods</p> <p>We enrolled 427 children ≤ 5 years old diagnosed with ALRTI attending the outpatient clinic or Emergency Department (ED) of Children Hospital, Cairo University during a one- year period. Nasopharyngeal aspirates were obtained from the patients, kept on ice and processed within 2 hours of collection. Immunoflourescent assay (IFA) for RSV was performed.</p> <p>Results</p> <p>91 cases (21.3%) had viral etiology with RSV antigens detected in 70 cases (16.4%). The RSV positive cases were significantly younger than other non-RSV cases (mean age 8.2 months versus 14.2 months, p <0.001). RSV cases had significantly higher respiratory rate in the age group between 2-11 months (mean 58.4 versus 52.7/minute, p < 0.001) and no significant difference in the mean respiratory rate in the age group between 12-59 months. More RSV cases required supplemental oxygen (46% versus 23.5%, p < 0.001) with higher rate of hospitalization (37.1% versus 11.2%, p < 0.001) than the non-RSV cases. 97% of RSV cases occurred in winter season (p < 0.001).</p> <p>Conclusion</p> <p>RSV is the most common viral etiology of ALRTI in children below 5 years of age, especially in young infants below 6 months of age. It is more prevalent in winter and tends to cause severe infection.</p

    Markers characterizing corneal damage during aging of rat

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    Aging is a biological phenomenon that involves an increase of oxidative stress associated with gradual degradation of the structure and function of the cornea. Gender differences and subsequent deterioration of cornea is an interesting topic, especially yet few data are available concerning the impact of age, especially on the corneal. One hundred male and female Wistar albino rats ages 3, 6, 18, 24, and 30 months (n=10 equal for male and female) were used. At the time interval, cornea were investigated by light and transmission electron microscopy (TEM), immunohistochemistry of caspase 3 (casp3), glial fibrillar acidic protein(GFAP) and CD45 and  flow cytometry of DNA, bcl-2-like protein 4 (BAX), transforming growth factor beta (TGF-β) and Cd45 (lymphocyte common antigen). Light and TEM investigation  revealed apparent deterioration of atrophy of corneal epithelium with vesicular vacuolar degeneration, hyalinization of stromal collagen fibrils and swelling and degeneration of the endothelial lining the descemet's membrane. There was apparent loss of keratocytes within corneal stroma. Immunohistochemistry of casp 3 and CD45 were markedly increased manifesting cell damage. GFAP showed apparent reduction of innervation of corneal stroma and endothelium layer. Flow cytometry of DNA, Bax and TGF revealed increased apoptic cell death of cornea of 30M-old rats. We concluded that aging contributed to an apparent increase of cellular damage of different corneal region associated with alterations of cell markers

    Structural and Functional adaptation of the lingual papillae of the Egyptian fruit bat (Rousettus aegyptiacus): Specific Adaptive feeding Strategies

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    The current investigation was directed to clarify the correlations between the feeding strategy and lingual structure of the Egyptian fruit bat captured from the Egyptian east desert. The current work depends on twelve adult Egyptian fruit bats that observed grossly and with the help of the stereo, light, and scanning electron microscope. There were three types of the lingual papillae; one mechanical filiform and two gustatory (fungiform and circumvallate). There were seven subtypes of filiform papillae were recognized on the seven lingual regions. There were scanty numbers of fungiform papillae distributed among the filiform papillae on the lingual tip and two lateral parts of apex and body while fungiform papillae completely absent in the median part. There were three circumvallate papillae. The central bulb of circumvallate papillae surrounded by one layer of two segmented circular annular bad. The lingual tip had cornflower-like and diamond-shaped filiform papillae. Histochemical results revealed that the lingual glands were a stronger AB-positive reaction and gave dark blue color, while the reaction for the PAS-stain was negative. Also, the glands exhibited a blue color as an indication of positive AB reactivity with combined AB-PAS staining

    Heterologous production of curcuminoids

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    Curcuminoids, components of the rhizome of turmeric, show several beneficial biological activities, including anticarcinogenic, antioxidant, anti-inflammatory, and antitumor activities. Despite their numerous pharmaceutically important properties, the low natural abundance of curcuminoids represents a major drawback for their use as therapeutic agents. Therefore, they represent attractive targets for heterologous production and metabolic engineering. The understanding of biosynthesis of curcuminoids in turmeric made remarkable advances in the last decade, and as a result, several efforts to produce them in heterologous organisms have been reported. The artificial biosynthetic pathway (e.g., in Escherichia coli) can start with the supplementation of the amino acid tyrosine or phenylalanine or of carboxylic acids and lead to the production of several natural curcuminoids. Unnatural carboxylic acids can also be supplemented as precursors and lead to the production of unnatural compounds with possibly novel therapeutic properties. In this paper, we review the natural conversion of curcuminoids in turmeric and their production by E. coli using an artificial biosynthetic pathway. We also explore the potential of other enzymes discovered recently or already used in other similar biosynthetic pathways, such as flavonoids and stilbenoids, to increase curcuminoid yield and activity.We acknowledge financial support from the Strategic Project PEst-OE/EQB/LA0023/2013, project reference RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462), project SYNBIOBACTHER (PTDC/EBB-BIO/102863/2008), and a doctoral grant (SFRH/BD/51187/ 2010) to J. L. Rodrigues, funded by Fundacao para a Ciencia e a Tecnologia. We thank the MIT-Portugal Program for support given to J. L. Rodrigues

    AdS/CFT beyond the unitarity bound

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    Scalars in AdSd+1{}_{d+1} with squared masses in the Breitenlohner-Freedman window d2/4m2<d2/4+1-d^2/4 \le m^2 < -d^2/4 +1 (in units with the AdS scale \ell set to 1) are known to enjoy a variety of boundary conditions. For larger masses m2>d2/4+1m^2 > -d^2/4 +1, unitarity bounds in possible dual CFTs suggest that such general boundary conditions should lead to ghosts. We show that this is not always the case as, for conformally-invariant boundary conditions in Poincar\'e AdS that would naively violate unitarity bounds, the system is generically ghost-free. Conflicts with unitarity bounds are avoided due to the presence of unexpected pure gauge modes and an associated infrared divergence. The expected ghosts appear when the IR divergence is removed either by deforming these boundary conditions or considering global AdS.Comment: 24 page

    Impact of the solvent capacity constraint on E. coli metabolism

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    <p>Abstract</p> <p>Background</p> <p>Obtaining quantitative predictions for cellular metabolic activities requires the identification and modeling of the physicochemical constraints that are relevant at physiological growth conditions. Molecular crowding in a cell's cytoplasm is one such potential constraint, as it limits the solvent capacity available to metabolic enzymes.</p> <p>Results</p> <p>Using a recently introduced flux balance modeling framework (FBAwMC) here we demonstrate that this constraint determines a metabolic switch in <it>E. coli </it>cells when they are shifted from low to high growth rates. The switch is characterized by a change in effective optimization strategy, the excretion of acetate at high growth rates, and a global reorganization of <it>E. coli </it>metabolic fluxes, the latter being partially confirmed by flux measurements of central metabolic reactions.</p> <p>Conclusion</p> <p>These results implicate the solvent capacity as an important physiological constraint acting on <it>E. coli </it>cells operating at high metabolic rates and for the activation of a metabolic switch when they are shifted from low to high growth rates. The relevance of this constraint in the context of both the aerobic ethanol excretion seen in fast growing yeast cells (Crabtree effect) and the aerobic glycolysis observed in rapidly dividing cancer cells (Warburg effect) should be addressed in the future.</p

    Curing of Plasmid pXO1 from Bacillus anthracis Using Plasmid Incompatibility

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    The large plasmid pXO1 encoding the anthrax toxin is important for the virulence of Bacillus anthracis. It is essential to cure pXO1 from B. anthracis to evaluate its role in the pathogenesis of anthrax infection. Because conventional methods for curing plasmids (e.g., curing agents or growth at elevated temperatures) can induce mutations in the host chromosomal DNA, we developed a specific and reliable method to eliminate pXO1 from B. anthracis using plasmid incompatibility. Three putative replication origins of pXO1 were inserted into a temperature-sensitive plasmid to generate three incompatible plasmids. One of the three plasmids successfully eliminated the large plasmid pXO1 from B. anthracis vaccine strain A16R and wild type strain A16. These findings provided additional information about the replication/partitioning of pXO1 and demonstrated that introducing a small incompatible plasmid can generate plasmid-cured strains of B. anthracis without inducing spontaneous mutations in the host chromosome

    Validation of tissue microarray technology in squamous cell carcinoma of the esophagus

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    Tissue microarray (TMA) technology has been developed to facilitate high-throughput immunohistochemical and in situ hybridization analysis of tissues by inserting small tissue biopsy cores into a single paraffin block. Several studies have revealed novel prognostic biomarkers in esophageal squamous cell carcinoma (ESCC) by means of TMA technology, although this technique has not yet been validated for these tumors. Because representativeness of the donor tissue cores may be a disadvantage compared to full sections, the aim of this study was to assess if TMA technology provides representative immunohistochemical results in ESCC. A TMA was constructed containing triplicate cores of 108 formalin-fixed, paraffin-embedded squamous cell carcinomas of the esophagus. The agreement in the differentiation grade and immunohistochemical staining scores of CK5/6, CK14, E-cadherin, Ki-67, and p53 between TMA cores and a subset of 64 randomly selected donor paraffin blocks was determined using kappa statistics. The concurrence between TMA cores and donor blocks was moderate for Ki-67 (κ = 0.42) and E-cadherin (κ = 0.47), substantial for differentiation grade (κ = 0.65) and CK14 (κ = 0.71), and almost perfect for p53 (κ = 0.86) and CK5/6 (κ = 0.93). TMA technology appears to be a valid method for immunohistochemical analysis of molecular markers in ESCC provided that the staining pattern in the tumor is homogeneous
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